Plant Transport Systems Revision Carousel

Question 1

What 2 components of phloem tissue are concerned with transport?

Answer 1

-Sieve tube elements
-Companion cells

Question 2

What is the purpose of parenchyma cells in xylem tissue?

Answer 2

Acts as a packing tissue to separate and support the vessels

Question 3

How do bordered pits form and what is their purpose?

Answer 3

Where lignification is incomplete, leaving gaps in the cell wall: the bordered pits in 2 adjacent vessels are aligned to allow water to leave one vessel and pass onto the next, as well as leave the xylem

Question 4

How are companion cells adapted for active loading?

Answer 4

Many mitochondria to produce ATP

Question 5

Plant transport systems consist of 2 major specialised vascular tissues. Name these, state their transport material and the direction of transport.

Answer 5

Xylem-water and soluble mineral ions up from root to leaves
Phloem-assimilates up or down

Question 6

Why do sieve tube elements contain no nucleus and very little cytoplasm?

Answer 6

Allows space for mass flow of sap to occur

Question 7

What is the purpose of lignin in xylem vessels?

Answer 7

Strengthens the vessel wall and prevents it from collapsing

Question 8

Describe three adaptation of xylem vessels that relate structure and function.

Answer 8

-Dead cells aligned end to end to form a continuous column
-Tubes are narrow so the water column doesn’t break easily and capillary action can be effective
-Bordered pits allow sideways movement of water between vessels
-Lignin allows stretching of xylem as plant grows (spiral or angular

Question 9

What tissue is found in between the xylem and phloem? What is its function?

Answer 9

Meristematic tissue (source of stem cells)